Metallocene Catalyzed Homopolymerization of Propylene with a C₂ Symmetric Isospecific Zirconecene/MMAO Catalysts under Different Polymerization Conditions

In this work, homopolymerization of propylene for synthesis of different molecular weights polypropylene was done using an isospecific metallocene catalyst by changing the polymerization conditions such as Al/Zr (Aluminium/Zirconium) ratio, temperature, pressure and polymerization time. The effects of the polymerization conditions on the molecular weight and other polymer properties have been discussed according to the results obtained. The results indicate that the activity of polymerization increased with increasing the Al/Zr mole ratio and reached a maximum value at a ratio of 2000. In relation to the mole ratio, the molecular weight also followed the same trend. The activity was also seen to increase with increase in temperature. The molecular weight increased with increasing the polymerization time at both 0°C and 25°C, but reduced with increase in time at 40°C. The increase of pressure also increased activity but lowered the molecular weight, indicating β-H elimination to the monomer.